Microwave magnatron burn out - is there any danger to health?

This morning our microwave blew up quite spectacularly - brown acrid smoke bellowing out of the vents and filling the kitchen.

I have inhaled quite a lot of the smoke after running in to get my daughter out of the room (the other daughter was still upstairs) and to open windows/switch on extractors etc.

I am concerned about any health risks as I can still taste the smoke in my mouth. Much moreso, I am concerned about our 10 week old twins going back into the house. My wife took them straight to her mum's and is back at the house cleaning everything she can and has all the windows open to vent as well as she can. Would we be better off staying away for a bit?

Whether or not this information worries you depends on how much smoke you inhaled, and also on the specific type of the magnetron in your microwave.

Some magnetrons have beryllium oxide ceramic insulators, which is a known carcinogen and can cause berylliosis, a lung disease, from a single exposure. Typically, however, this warning only applies to crushed magnetons. IIRC, it's more associated with people who worked underground in enclosed spaces around radar equipment.

The smoke you inhaled is probably from wiring insulation and consequently is fairly harmless. The rest of the magnetron is copper and so not an issue. Personally, I wouldn't be concerned.